6.5.4 Terrestrial Beacon System Positioning

37.3553GPPLTE Positioning Protocol (LPP)Release 17TS

6.5.4.1 TBS Location Information

– TBS-ProvideLocationInformation

The IE TBS-ProvideLocationInformation is used by the target device to provide TBS location measurements to the location server. It may also be used to provide TBS positioning specific error reason.

— ASN1START

TBS-ProvideLocationInformation-r13 ::= SEQUENCE {

tbs-MeasurementInformation-r13 TBS-MeasurementInformation-r13 OPTIONAL,

tbs-Error-r13 TBS-Error-r13 OPTIONAL,

…

}

— ASN1STOP

6.5.4.2 TBS Location Information Elements

– TBS-MeasurementInformation

The IE TBS-MeasurementInformation is used by the target device to provide TBS location measurements to the location server.

— ASN1START

TBS-MeasurementInformation-r13 ::= SEQUENCE {

measurementReferenceTime-r13 UTCTime OPTIONAL,

mbs-SgnMeasList-r13 MBS-BeaconMeasList-r13 OPTIONAL, — Cond MBS

…

}

— ASN1STOP

Conditional presence	Explanation
MBS	The field is mandatory present if the TBS-MeasurementInformation is provided for an MBS system; otherwise it is not present.

TBS-MeasurementInformation field descriptions
measurementReferenceTime This field provides the UTC time when the TBS measurements are performed and should take the form of YYMMDDhhmmssZ.
mbs-SgnMeasList This field provides the MBS measurements for up to 64 MBS beacons.

– MBS-BeaconMeasList

The IE MBS-BeaconMeasList is used by the target device to provide MBS location measurements to the location server, as defined in the MBS ICD [24].

— ASN1START

MBS-BeaconMeasList-r13 ::= SEQUENCE (SIZE(1..64)) OF MBS-BeaconMeasElement-r13

MBS-BeaconMeasElement-r13 ::= SEQUENCE {

transmitterID-r13 INTEGER (0..32767),

codePhase-r13 INTEGER (0..2097151),

codePhaseRMSError-r13 INTEGER (0..63),

…,

[[ rssi-r14 INTEGER (-130..-30) OPTIONAL

]]

}

— ASN1STOP

MBS-BeaconMeasList field descriptions
transmitterID This field contains the MBS transmitter identifier.
codePhase This field contains the value of the code-phase measurement made by the target device for the particular beacon signal at the time of measurement in the units of ms. MBS specific code phase measurements (e.g. chips) are converted into unit of ms by dividing the measurements by the nominal values of the measured signal chipping rate. Scale factor 2-21 milli‑seconds, in the range from 0 to (1-2-21) milli‑seconds.
codePhaseRMSError This field contains the pseudorange RMS error value. This parameter is specified according to a floating-point representation shown in the table below.
rssi This field provides an estimate of the received signal strength from the MBS beacon as referenced to the UE antenna connector. If the estimated received signal strength for the MBS beacon is less than -130 dBm, the UE shall report an RSSI value of -130. If the estimated received signal strength for the MBS beacon is greater than -30 dBm, the UE shall report an RSSI value of -30. Scale factor 1 dBm.

floating-point representation

Index	Mantissa	Exponent	Floating-Point value, xi	Pseudorange value, P [m]
0	000	000	0.5	P < 0.5
1	001	000	0.5625	0.5 <= P < 0.5625
i	x	y	0.5 * (1 + x/8) * 2y	xi-1 <= P < xi
62	110	111	112	104 <= P < 112
63	111	111	—	112 <= P

6.5.4.3 TBS Location Information Request

– TBS-RequestLocationInformation

The IE TBS-RequestLocationInformation is used by the location server to request location information for TBS-based methods from the target device.

— ASN1START

TBS-RequestLocationInformation-r13 ::= SEQUENCE {

mbsSgnMeasListReq-r13 BOOLEAN,

…,

[[ mbsAssistanceAvailability-r14 BOOLEAN OPTIONAL, — Need ON

mbsRequestedMeasurements-r14 BIT STRING {

rssi (0)} (SIZE(1..8)) OPTIONAL — Need ON

]]

}

— ASN1STOP

TBS-RequestLocationInformation field descriptions
mbsSgnMeasListReq This field indicates whether the target device is requested to report MBS measurements in TBS‑MeasurementInformation IE or not. TRUE means requested.
mbsAssistanceAvailability This field indicates whether the target device may request additional MBS assistance data from the server. TRUE means allowed and FALSE means not allowed.
mbsRequestedMeasurements This field indicates the additional MBS measurements requested and may only be included if mbsSgnMeasListReq is set to TRUE. This field is represented by a bit string, with a one‑value at the bit position means the particular measurement is requested; a zero‑value means not requested. The following measurement requests can be included. rssi: Beacon signal strength at the target

6.5.4.4 TBS Capability Information

– TBS-ProvideCapabilities

The IE TBS-ProvideCapabilities is used by the target device to indicate its capability to support TBS and to provide its TBS location capabilities to the location server.

— ASN1START

TBS-ProvideCapabilities-r13 ::= SEQUENCE {

tbs-Modes-r13 BIT STRING { standalone (0),

ue-assisted (1),

ue-based (2)} (SIZE (1..8)),

…,

[[ mbs-AssistanceDataSupportList-r14 MBS-AssistanceDataSupportList-r14 OPTIONAL,

periodicalReportingSupported-r14 PositioningModes OPTIONAL,

mbs-ConfigSupport-r14 BIT STRING { tb1 (0),

tb2 (1),

tb3 (2),

tb4 (3)} (SIZE (1..8)) OPTIONAL,

mbs-IdleStateForMeasurements-r14 ENUMERATED { required } OPTIONAL

]],

[[ scheduledLocationRequestSupported-r17 ScheduledLocationTimeSupportPerMode-r17 OPTIONAL

]]

}

— ASN1STOP

TBS-ProvideCapabilities field descriptions
tbs-Modes This field specifies the TBS mode(s) supported by the target device. This is represented by a bit string, with a one‑value at the bit position means the particular TBS mode is supported; a zero‑value means not supported.
mbs-AssistanceDataSupportList This list defines the MBS assistance data supported by the target device. This field shall be present if the target device supports MBS assistance data.
periodicalReportingSupported This field, if present, specifies the positioning modes for which the target device supports periodicalReporting. This is represented by a bit string, with a one‑value at the bit position means periodicalReporting for the positioning mode is supported; a zero‑value means not supported. If this field is absent, the location server may assume that the target device does not support periodicalReporting in CommonIEsRequestLocationInformation.
mbs-ConfigSupport This field specifies the MBS configurations supported by the target device. This field shall be present if the target device supports MBS [24].
mbs-IdleStateForMeasurements This field, if present, indicates that the target device requires idle state to perform MBS measurements.
scheduledLocationRequestSupported This field, if present, specifies the positioning modes for which the target device supports scheduled location requests – i.e., supports the IE ScheduledLocationTime in IE CommonIEsRequestLocationInformation – and the time base(s) supported for the scheduled location time for each positioning mode. If this field is absent, the target device does not support scheduled location requests.

– MBS-AssistanceDataSupportList

The IE MBS-AssistanceDataSupportList is used by the target device to indicate its capability to support MBS Assistance Data and to provide its capabilities to the location server.

— ASN1START

MBS-AssistanceDataSupportList-r14 ::= SEQUENCE {

mbs-AcquisitionAssistanceDataSupport-r14 BOOLEAN,

mbs-AlmanacAssistanceDataSupport-r14 BOOLEAN,

…

}

— ASN1STOP

MBS-AssistanceDataSupportList field descriptions
mbs-AcquisitionAssistanceDataSupport This field specifies whether the target device supports MBS Acquisition Assistance Data. TRUE means supported.
mbs-AlmanacAssistanceDataSupport This field specifies whether the target device supports MBS Almanac Assistance Data. TRUE means supported.

6.5.4.5 TBS Capability Information Request

– TBS-RequestCapabilities

The IE TBS-RequestCapabilities is used by the location server to request TBS positioning capabilities from a target device.

— ASN1START

TBS-RequestCapabilities-r13 ::= SEQUENCE {

…

}

— ASN1STOP

6.5.4.6 TBS Error Elements

– TBS-Error

The IE TBS-Error is used by the location server or target device to provide TBS error reasons to the target device or location server, respectively.

— ASN1START

TBS-Error-r13 ::= CHOICE {

locationServerErrorCauses-r13 TBS-LocationServerErrorCauses-r13,

targetDeviceErrorCauses-r13 TBS-TargetDeviceErrorCauses-r13,

…

}

— ASN1STOP

– TBS-LocationServerErrorCauses

The IE TBS-LocationServerErrorCauses is used by the location server to provide error reasons for TBS positioning to the target device.

— ASN1START

TBS-LocationServerErrorCauses-r13 ::= SEQUENCE {

cause-r13 ENUMERATED { undefined,

…,

assistanceDataNotSupportedByServer-v1420,

assistanceDataSupportedButCurrentlyNotAvailableByServer-v1420

},

…

}

— ASN1STOP

– TBS-TargetDeviceErrorCauses

The IE TBS-TargetDeviceErrorCauses is used by the target device to provide error reasons for TBS positioning to the location server.

— ASN1START

TBS-TargetDeviceErrorCauses-r13 ::= SEQUENCE {

cause-r13 ENUMERATED { undefined,

thereWereNotEnoughMBSBeaconsReceived,

…,

assistanceDataMissing-v1420

},

…

}

— ASN1STOP

TBS-TargetDeviceErrorCauses field descriptions
cause This field provides a TBS specific error cause.

6.5.4.7 TBS Assistance Data

– TBS-ProvideAssistanceData

The IE TBS-ProvideAssistanceData is used by the location server to provide assistance data to assist in position estimation at the UE (e.g. for UE‑based mode) and/or to expedite the acquisition of TBS signals. It may also be used to provide TBS positioning specific error reasons.

— ASN1START

TBS-ProvideAssistanceData-r14 ::= SEQUENCE {

tbs-AssistanceDataList-r14 TBS-AssistanceDataList-r14 OPTIONAL, — Need ON

tbs-Error-r14 TBS-Error-r13 OPTIONAL, — Need ON

…

}

— ASN1STOP

6.5.4.8 TBS Assistance Data Elements

– TBS-AssistanceDataList

The IE TBS-AssistanceDataList is used by the location server to provide the TBS specific assistance data to the UE.

— ASN1START

TBS-AssistanceDataList-r14 ::= SEQUENCE {

mbs-AssistanceDataList-r14 MBS-AssistanceDataList-r14 OPTIONAL, — Need ON

…

}

MBS-AssistanceDataList-r14 ::= SEQUENCE (SIZE (1..maxMBS-r14)) OF MBS-AssistanceDataElement-r14

MBS-AssistanceDataElement-r14 ::= SEQUENCE {

mbs-AlmanacAssistance-r14 MBS-AlmanacAssistance-r14 OPTIONAL, — Need ON

mbs-AcquisitionAssistance-r14 MBS-AcquisitionAssistance-r14 OPTIONAL, — Need ON

…

}

— ASN1STOP

– MBS-AlmanacAssistance

The IE MBS-AlmanacAssistance is used by the location server to provide LLA of MBS transmitters to enable position estimation at the UE.

— ASN1START

MBS-AlmanacAssistance-r14 ::= SEQUENCE {

transmitterID-r14 INTEGER (0..32767),

transmitterLatitude-r14 BIT STRING (SIZE (26)),

transmitterLongitude-r14 BIT STRING (SIZE (27)),

transmitterAltitude-r14 BIT STRING (SIZE (15)),

timeCorrection-r14 INTEGER (0..25) OPTIONAL, — Need ON

…

}

— ASN1STOP

MBS-AlmanacAssistance field descriptions
transmitterID This field specifies the MBS transmitter ID [24].
transmitterLatitude This field specifies latitude of the MBS transmitter, degrees. Scale factor 4/220 decimal degrees, added to -90°. Valid range -90° to 90° [24].
transmitterLongitude This field specifies longitude of the MBS transmitter, degrees. Scale factor 4/220 decimal degrees, added to -180°. Valid range -180° to 180° [24].
transmitterAltitude This field specifies altitude of the MBS transmitter, metres. Scale factor 0.29 metres, added to -500 metres. Valid range -500 to 9002.43 metres [24].
timeCorrection This field contains the residual timing error for a particular beacon, in units of nano-seconds, in the range from 0 to 25. This field is used for UE-based mode only, by subtracting from the codePhase measurement made by the target device [24].

– MBS-AcquisitionAssistance

The IE MBS-AcquisitionAssistance is used by the location server to provide parameters that support acquisition of the MBS signals [24].

— ASN1START

MBS-AcquisitionAssistance-r14 ::= SEQUENCE {

transmitterID-r14 INTEGER (0..32767) OPTIONAL, — Need ON

mbsConfiguration-r14 ENUMERATED {tb1, tb2, tb3, tb4, …} OPTIONAL, — Need ON

pnCodeIndex-r14 INTEGER (1..128) OPTIONAL, — Need ON

freq-r14 INTEGER (919750000..927250000) OPTIONAL, — Need ON

…

}

— ASN1STOP

MBS-AcquisitionAssistance field descriptions
transmitterID This field contains the MBS transmitter identifier [24].
mbsConfiguration This field specifies MBS configuration as defined in the MBS ICD [24].
pnCodeIndex This field specifies the index of the MBS PN code [24].
freq This field specifies the MBS signal centre frequency in units of Hz [24].

6.5.4.9 TBS Assistance Data Request

– TBS-RequestAssistanceData

The IE TBS-RequestAssistanceData is used by the target device to request TBS assistance data from a location server.

— ASN1START

TBS-RequestAssistanceData-r14 ::= SEQUENCE {

mbs-AlmanacAssistanceDataReq-r14 BOOLEAN,

mbs-AcquisitionAssistanceDataReq-r14 BOOLEAN,

…

}

— ASN1STOP